Carburetor



June 8, 1965 J. 5. REID ETAL CARBURETOR 6 Sheets-Sheet 1 Filed May 29, 1962 INVENTORxS. 75/755 6. REID June 8, 1965 J. s. REID ETAL 3,188,062

- CARBURETOR Filed May 29, 1962 6 Sheets-Sheet 4 BY Wynn, Q 2m June 8, 1965 J. s. REID ETAL CARBURETOR Filed May 29, 1962 6 Sheets-Sheet 5 wfi 5 aw U H mm MN r if June 8, 1965 J. s. REID ETAL 3,188,052

CARBURETOR Filed May 29, 1962 6 Sheets-Sheet 6 INVENTORS'. WIVES REM) Y flew/w W BROCK United States Patent 3,188,062 CAREURETOR .iames S. Reid, Hudson, and Henry W. Brock, Willcnghby, Uhio, assignors to The Standard Products (Company, Cleveland, Uhio, a corporation of (Ethic Filed May 29, 1962, Ser. No. 198,644 3 Claims. (Cl. 261-41) This invention relates generally to carburetors especially designed for use with internal combustion engines or the like and more particularly to carburetor structures, with which an overall high engine efiiciency may be obtained for all conditions of engine operation.

Before a combustible fuel such as gasoline commonly in use today is supplied to an internal combustion engine for ignition therein, it is required to be carbureted with a predetermined amount of air, which mixture of fuel and air is generally referred to as carbureted fuel. This carbureted fuel provides an explosive mixture which, when fed into the engine is ignited so as to provide sufiicient energy to run the same.

As is known in the art, the amount of energy per volume of carbureted fuel is directly related to the ratio of fuel to air in said mixture.

For example, it has been determined that in a carbu-reted fuel mixture containing approximately 15 parts of air to 1 part gasoline fuel of present day standards proportioned by weight, a combustible mixture will be obtained which, when applied to and ignited in an internal combustion engine maximum efliciency of operation of the engine will be obtained.

As will be further recognized, an internal combustion engine that is used in an automotive vehicle or the like is required to operate under various load conditions, and consequently a carburetor designed for use with said engine must be operable to supply the proper mixture of fuel and air as above defined to said engine for all conditions. of operation thereof and also during the transitional periods during which the engine is changing from one operational condition to another.

For example, if the engine in an automotive vehicle is running at idle speed and the controls for said engine are actuated to accelerate the vehicle, the conventional carburetor changes from an idle condition of operation for said engine to an accelerated condition and consequently if the automobile is to be sustained at said accelerated speed, the carburetor and controls therefor must be operable to provide a larger quantity of carbureted fuel to said engine which, for maximum eflicient operation, should have approximately the same ratio of gasoline fuel to air, namely 15 parts air per 1 part fuel.

In like manner, assuming that the vehicle is running at a somewhat higher speed than the idle speed which may be hereinafter defined as a cruising speed, and it is then desirable to decelerate said vehicle, the engine controls are actuated to return the conventional carburetor to its idle position preparatory to decreasing said vehicle velocity.

As is well known, in the intake manifold of an internal combustion engine gasoline fuel in the carbureted mixture has a tendency to condense onto the walls of said manifold thus forming a dense fuel. This condensation is not of primary importance while the engine is running at an accelerated speed, however when the engine is to be decelerated, and the carburetor is returned to idle condition, said carburetor during the initial portion of the deceleration cycle is not capable of providing sufficient air to mix with this dense fuel. Consequently, the byproducts .of combustion during this initial period contain a greater proportion of hydrocarbons, unburned fuel and other volatile products than would otherwise be present if proper carburetion was obtained Eddbfidl Patented June 8, 1965 ICC Conventional carburetors in use today have heretofore been provided with control elements that function at various engine speeds in an attempt to thus effect an eflicient carburetion of the fuel and air throughout substantially all conditions of engine operation which may be encountered.

However, a distinct disadvantage in prior control systems has been their inability to provide a proper carbureted fuel mixture during the transitional periods when the engine is changing from one operating condition to another, and particularly during the deceleration transitional period as above described when the engine is decelerating from a cruising speed to an idle speed.

It is therefore a primary object of the present invention to provide a new and improved carburetor structure especially designed for use with an internal combustion engine and the like, and which structure is particularly applicable to provide a predetermined optimum mixture of carbureted fuel to its associated engine during the transitional period the engine is decelerating from a high to a low speed of operation.

Another object of the present invention is the provision of a new and improved carburetor structure especially designed for use with an internal combustion engine or the like and which structure is operable to provide a substantially constant proportion of fuel to air in a carbureted fuel mixture delivered to the engine during the deceleration period and which structure is responsive to the engine operation during said transitional deceleration period.

Another object of the present invention is the provision of a new and improved carburetor structure especially designed for use with an internal combustion engine and the like and which structure is especially applicable to provide an optimum mixture of carbureted fuel to the engine during the transitional period when the engine is decelerating from a high to a low speed, and which carburetor structure is responsive to a variable operational characteristic of the engine during said transitional period.

Yet another object of the present invention is the provision of a carburetor structure as is defined hereinabove, and which is especially designed for use with an intern-a1 combustion engine which exhibits a transitional change in internal vacuum conditions while the same is decelerating from a relatively high to a low engine velocity, and which carburetor structure is responsive to said internal vacuum conditions effective to provide an optimum mixture of fuel and air to said engine.

Another object of the present invention is to provide a carburetor structure as is defined hereinabove, and which is operable to provide an optimum carbureted fuel mixture to an internal combustion engine for all conditions of operation of said engine.

Additional objects and advantages of the carburetor structure of the present invention will be apparent to one skilled in the art to which it pertains and upon reference to the following disclosure of several preferred embodiments thereof and which are illustrated in the drawings accompanying this specification, forming therefor a part hereof and in which:

FIG. 1 is a front elevation of a carburetor structure embodying the present invention;

FIG. 2 is a' plan View being shown partly in section to illustrate otherwise hidden components thereof;

FIG. 3 is a side elevation showing the adjustable idle fuel controls for the carburetor structure;

FIG. 4 is a fragmentary View of one of the needle valves used in the valve assembly of the carburetor structure;

FIG. 5 is a sectional view of a modified idle air valve assembly illustrating the part of the carburetor housing within the circle identified at 5 in FIG. 2;

FIG. 6 is a plan View shown partly in section of a second embodiment of carburetor structure;

FIG. 7 is a side elevational view of a third embodiment of carburetor structure;

FIG. 8 is a plan view of the structure of FIG. 7; and,

FIG. 9 is a sectional View taken along the plane as indicated approximately by the line 99 in FIG. 8.

Briefly, the carburetor structure of the present invention is herein incorporated into a conventional downdraft type of carburetor assembly and is intended to be substituted for the structure and controls thereof which function to provide idle fuel and air to said assembly.

However, as will be later apparent, the inventive concepts of the instant carburetor structure may be readily applicable to other types of assemblies and the following disclosure is not intended to define any limitations as to its use and/or scope.

Referring now particularly to FIG. 1, a conventional down-draft carburetor assembly is herein shown and includes a body 4 which is intended to be disposed in an upright position and connected to the intake manifold of an internal combustion engine in the usual manner.

The instant carburetor assembly is of the type commonly referred to as a two barreled carburetor inasmuch as it has two separate barrels in which fuel and air are mixed preparatory to submission of the carbureted fuel to the intake manifold. As will likewise later be apparent, the inventive concepts as are disclosed herein may be readily adapted to any carburetor structure having only one or more than several carburetor barrels.

In adapting the down-draft type of carburetor for use with an internal combustion engine for an automotive vehicle the carburetor is connected to a fuel supply usually through a reservoir or float chamber such as is illustrated at and through suitable internal porting formed in the body t to a position adjacent the main venturi area of said body. 1

With fuel entering the carburetor, air is drawn into its upper end through its air horn and filter unit as indicated at 7 whereby as said air passes downwardly through the carburetor barrels it draws the fuel into the air stream whereby a carbureted fuel mixture is provided to the intake of the engine.

As will be understood, a throttle or butterfly valve is disposed in each of the barrels and is usually carried on a single shaft which is suitably rotatably mounted in the carburetor body so as to have its end thereof extending outwardly from the same and attached by linkage 16 to a manual throttle or accelerator control disposed in the operators station of the vehicle.

As is likewise well known, suitable conventional idle controls function with the aforesaid throttle valves which are moved by the linkage 16 to idle position as to cause a minimum quantity of fuel and air to be directed to the engine intake for idle engine operation whereas a greater quantity of air and fuel is directed to said engine by additional conventional controls operating in conjunction with said throttle valves being movable to an open throttle position, said valves being adjustably movable in said carburetor by the vehicle operator to thereby control the c-arbureted fuel supply in accordance with the operation requested of the engine.

As aforementioned, the carburetor structure of the present invention is incorporated into a conventional carburetor assembly as thus described, being operational in conjunction therewith to control the mixture of fuel and air to the intake manifold of the associated engine, and is particularly operable during the transitional period when the engine is decelerating from a relatively high velocity to a low or idle condition to supply said engine with a suficient quantity of carbureted fuel which mixture has an optimum proportion of fuel to air, and which likewise is substantially constant during said period.

More specifically, to adapt the carburetor structure of the present invention to the particular carburetor assembly herein disclosed, the aforementioned idle controls and idle valve or valves heretofore used in said conventional assembly are rendered inoperable so as not to eifect any regulation of operation of the combined structure.

With particular reference now directed to FIG. 2, the carburetor structure of the present invention comprises a platelike housing 20 which, in its instant application is preferably somewhat rectangular in configuration thus defining opposed longitudinally extending side walls 20a and 2M) and transverse end walls 20c and 2001.

The housing 21 is intended to be sandwiched between the base of the body 4 of the conventional carburetor and the intake manifold of the engine, being formed, in addition, with holes 21 which are disposed to accommodate the mounting bolts for said carburetor body to secure said combined assembly onto said manifold.

The housing 20 is formed with a pair of circular chambers 22 and 23 respectively, which are spaced apart so as to define a longitudinal extension of each of the barrels in the carburetor body 4.

To provide a supply of air to said chambers, an inlet port 24 formed in said housing is seen to communicate with a bore 32 extending longitudinally therethrough adjacent its one side wall Zeb, said bore likewise communicating directly opposite said inlet port with a transfer port 35, the latter extending transversely across said housing and communicating at its opposite end centrally with port 38. Port 38, in turn, communicates at its opposite ends with the chambers 22 and 23 which, as is aforementioned define a continuation of the carburetor barrels of the conventional carburetor assembly, said chambers being therefore downstream from the butterfly throttle valve in each of said barrels.

A piston 40 is disposed in the aforementioned bore 32 being freely slidable therein, said piston having enlarged bell ends 49a and 4% integrally formed with a central rod portion 400 which is seen to be of substantially reduced diameter relative to the said bore thus defining an annular air chamber therebetween as identified at 42.

A cam follower rod 44 is likewise disposed in the bore 32 being freely slidable therein, its one end being adapted to abut against the end of bell portion dilb of the piston 40, its opposite end projecting outwardly from said bore 32 and rotatably mounting a roller 46.

Cam 47 carried on a cam plate 48 attached to the housing end wall Zed is provided with a cam surface 49 disposed as to accommodate the aforementioned roller 46, said cam being reciprocably actuatable on said plate as will be hereinafter described, effective to slidably move the rod 44 through the bore 32.

Spring 51 hearing on one end against a ring 52 carried on the rod 44 and at its opposite end against a shoulder formed in the housing 20 surrounding the aforementioned bore 32 is effective to urge said rod and roller into positive engagement with the cam surface 49.

The bell portion 40:; of the piston 46 is seen to be centrally provided with a boss 54 projecting axially outwardly therefrom, and an adjusting screw as identified at 56 which is threadedly disposed in plug 57 adjustably mounted in the opposite end of the bore 32 is adapted to engage the end of said boss.

A suitable coil spring as is indicated at 61 is disposed in the aforementioned bore 32, its opposed ends engaging the plug 57 and the end wall of the bell portion 40a surrounding the aforementioned boss 54 being thus effective to urge the piston 40 into engagement with the rod 44.

One end of a conduit 62 is connected to the aforesaid inlet port 23 and its opposite end preferably to the air filter unit 7 to thereby provide a supply of clean filtered air to said port.

On attachment of the housing 20 of the instant carburetor structure to the intake manifold of an internal combustion engine so as to be downstream from the throttle valve of the conventional carburetor and between the latter and the intake of the engine, the valve assembly just described is operable to provide a predetermined quantity of air to the carburetor whereby the engine will operate at maximum efficiency, particularly during the transitional period of deceleration when the engine decreases in velocity from a relatively high rate to an idle condition and likewise thereafter during said idle condition.

To accomplish this, with the engine operating at idle speed and the throttle valve of the conventional assembly moved to its idle position whereby a predetermined quantity of fuel is drawn into the carburetor by valve structure later to be described, the piston 4% is moved to an idle position in the valve bore 32 so as to permit air to pass into said bore of a volume sufiicient to mix with the idle fuel, said mixture having by proportion approximately 15 parts air to 1 part fuel. The piston 39 is located in its idle position by adjusting the cam 47 on its plate so as to locate the central portion of the piston 4% opposite the inlet port 23 and thereby permit only a predetermined volume of air to enter and pass there through and into its communicating port 35.

The cam plate 43, as best seen in FIGS. 1 and 2, is mounted on the end wall 2% of the housing 26, preferably below the throttle linkage 16 for the conventional carburetor assembly, and the cam 47 is provided with an elongated slot 47a which accommodates a bolt 4712 thereby anchoring said cam to said plate.

The cam 47 is connected to the aforesaid linkage 16, and is slidably movable along its supporting plate in response to the vehicle operator actuating the throttle controls.

For this purpose, a bracket 70 is attached by fastener 71 to the shaft 13 of the conventional carburetor assembly so as to be rotatable about said shaft, said bracket in turn having a curved slot 72 formed therein, spaced from its pivotal connection and preferably of constant radius about said shaft. An adjusting screw 73 disposed in said slot anchors said bracket to the linkage 16 whereby said bracket will swing about shaft 13 as said linkage is swing=- ably actuated by the throttle controls.

A post 75 mounted on the cam 47 is provided with spaced arms 75a to which is journaled a cylindrical guide 77.

Rod 78 is slidably disposed in said guide and has its one end swivelly attached at 80 on the end of the bracket 7t) opposite its linkage connection 16. The opposite end of said rod is preferably threaded so as to accommodate a pair of adjusting nuts 79 and 8%, one of said nuts being disposed on each side of said guide 77. Coil spring 81 disposed on rod 78 is seen to be interposed be tween the nut 79 adjacent the end of said rod and the guide 77. 7

With this linkage assembly, it will be apparent that by adjusting nuts 79 and 8% the cam 47 may be slidably moved along its supporting plate 48 to thus locate said cam in an idle position, this adjustment being undertaken with the linkage 16 in its idle position.

As the cam 47 is being positioned in this manner the cam rod 44 is likewise slidably moved accordingly through bore 32 and the screw 56 may then be adjusted so as to retain the piston 4% in positive engagement with the rod 44, said dual adjustment being made to locate the center part Me of said piston in a position such as is shown in FIG. 2 so as to permit the proper proportion of air to enter into the housing chambers 22 and 23 and to mix with the idle fuel to thus sustain efficient engine operation at idle condition.

Subsequent to this adjustment, the screw 56 may then be backed olf so that the piston 40 is maintained in positive pressure engagement with the rod 44 by coil spring 61.

Thereafter, as the throttle is advanced so as to run the engine at a speed higher than idle speed, the linkage interconnecting said throttle and cam 47 is operable to slide the latter along its cam plate 48 in a downward direction as is viewed in FIG. 2 which is eflective to slide the rod 44 and piston 40 to the left through the valve bore 32 whereby the end bell portion 40b of piston 40 is moved across inlet port 24 to proportionally diminish the air inlet flow therethrough. At a predetermined engine speed, the piston has been moved through the valve bore 32 to a position wherein port 24 is substantially sealed from said bore thus cutting off any idle air flowing into the connecting ports 35 and 38.

At this engine speed, the convetnional carburetor assembly functions in the normal manner to provide suflicient air to the main venturi to sustain proper carburetion.

As is well known, an internal combustion engine running at a comparatively constant speed above its idle speed has an intake manifold vacuum which can be measured to have a magnitude of approximately 16 to 19 inches of mercury.

It is further recognized in the art that upon initial deceleration of said engine from said elevated speed the operator has released the carburetor controls so that the carburetor returns to its idle condition while the engine is still running at said elevated speed. Consequently, the manifold vacuum increases almost instantaneously to a magnitude of approximately 26 to 28 inches mercury and as the deceleration of the engine continues said vacuum progressively lessens until the engine reaches its idle condition at which time said vacuum again returns to a magnitude of 16 to 19 inches of mercury.

The transitional variation of the vacuum condition in the intake manifold of the engine is utilized in the carburetor structure of the present invention to provide a variable control for the idle air valve assembly which in turn is operable to provide a variable quantity of air to the carburetor subsequent to the conventional controls of the same being returned to idle condition.

To accomplish this, a port identified at is formed in the housing 2% and communicates with the valve bore 32 adjacent housing end wall Zita as is viewed in FIG. 2 so as to be between the end bell 40a of the piston 40 and the bore plug 57. A suitable conduit as is indicated at 87 has its one end connected to said port and its opposite end (not shown) is connected to the intake manifold.

With the engine operating at an elevated speed the inlet manifold vacuum is within the range of 16 to 19 inches of mercury, and the piston 40, as aforesaid, is located in sealing relation with the inlet port 24.

Thereafter, as the engine deceleration is initiated by the operator and the vacuum condition in the intake manifold of said engine increases to approximately a magnitude of 26 to 28 inches of mercury, this increase vacuum is effective to literally suck the piston 40 rapidly toward the left end of the valve bore 32 as viewed in FIG. 2 a distance sulficient to carry the right end bell ltib thereof clear of the inlet port 24 whereby a maximum quantity or slug of air may then pass through said port and connected transfer ports 3-5 and 38 to the housing chambers 22 and 23. Said inlet air therefore mixes with the dense fuel already metered by said carburetor into said manifold as aforementioned, the quantity of said inlet air being sutiicient to thereby provide an optimum explosive mixture to the engine.

As the engine continues to decelerate and approaches its idle speed, the vacuum in the intake manifold also progressively decreases and approaches a vacuum of a magnitude of approximately 16 inches of mercury.

Consequently, a decrease in vacuum is also experienced in the valve bore 32 whereby the spring 61 moves the piston 4t} and rod 44 in a reverse direction or to the right as is shown in FIG. 2 effective to return said piston to its idle position.

As the right end hell 4% of piston 40 passes again across the inlet port 24 air is momentarily sealed from the valve bore 32 but the movement of the piston is sufficient so as not to cause any deleterious effects in engine operation.

With this assembly, it will now be recognized that the carburetor structure of the present invention is responsive to transitional characteristics of an internal combustion engine (transitional vacuum conditions) particularly during the deceleration cycle when the engine is decelerating from a relatively high speed to an idle speed being operable to variably regulate the quantity of air that is supplied to the carburetor.

As previously mentioned the instant carburetor structure is also responsive to the transititional engine characteristics to regulate the quantity of fuel supplied to said engine, particularly during the deceleration cycle of the latter.

For this purpose, the housing 21) is provided with a valve bore 91 extending longitudinally therethrough adjacent the opposite housing side wall 211a, being therefor disposed on the opposite side of the housing chambers 22 and 23.

One end of said bore 91 communicates with an enlarged chamber 92 disposed so as to be in longitudinal prolongation to the same, said chamber slidably accommodating a piston rod 93 therein. A piston 94 is formed integrally on one end of said rod, being slidably engagable in fluid leak-proof relation with the chamber wall, the opposite end of said rod rollably mounting a roller 96.

A cam 97 carried on the aforementioned cam plate 48 in a manner similar to the mounting of cam 37 is provided with a cam surface 98 which is intended to ac commodate said roller.

A valve rod as is indicated in its entirety at 1112 is disposed centrally within the bore 91, its one end extending into the chamber 92 so as to be in position to abut the adjacent end of the piston 24.

A suitable coil spring 103, interposed between the opposite end of said rod 102 and a closure plug 105 thread: edly disposed in the opposite end of the aforementioned bore 91, is operable to urge said rod 1112 into pressure engagement with the piston 94 and hence likewise urges the roller 96 into positive engagement with the aforementioned cam surface 98.

A pair of internally threaded bores 1116 and 108 are formed in said housing extending inwardly from the side wall 29a and communicating with the underside portion of said housing bore 91 in longitudinal spaced relation therealong, each of said bores, in turn, communicating at its inner end with one end of a valve bore 112, 11 3 respectively, formed preferably of stepped configuration and which has an inlet port 114, 115 at its innermost end communicating with one of the housing chambers 22, 2-3.

As best seen in FIG. 2, the upper surface Ztle of the housing 20 is provided with a groove having a central portion 120 extending between the chambers 22 and 23 and which communicates at one end with diverging branch grooves 123 and 124, each of the latter, in turn, communicating respectively through port 123a, 124a with one of the valve bores 112, 113.

The opposite end of the central portion of groove 120 connects with the inner end of each of a pair of branch channels 126 and 127 which, at the opposite end thereof communicate with one of a pair of transfer ports 131, 132 formed in the body 4 of the conventional carburetor as seen in FIG. 3, and which, in turn, extend upwardly therethrough to connect with the main fuel inlet to the carburetor barrels.

With the housing 20 disposed below the craburetor body 4 of the conventional assembly, the base of said body overlies the aforesaid groove 120 to thus define a fuel passage connecting between the main fuel inlet and the housing chambers 22 and 23. j

A needle valve assembly as identified in FIG. 2 in its entirety at 133, is disposed in each of the bores 1M, 1118, each said assembly including an elongated needle valve 134, the head end 134a of which interfits an adjusting 8 plug 136 threadedly mounted in the associated bore, said valve being securely attached to said plug by fastener 137 so as to be rotatably adjustable by the latter in said bore.

The needle valve 134 of each assembly is formed having a central shank 141 provided on its front end with a rod portion 141 the latter, in turn, having a bullet-shaped nose 143.

A narrow radial groove 151i is formed in said rod portion and adjoining nose of said needle valve, said groove, as best seen in FIG. 4, being generally semi-circular in configuration.

The shank and rod portions of said needle valve extend into the valve bore connecting with the housing bore so as to locate the nose 143 thereof in close proximity to the inlet port 1141, associated therewith, the diameters of said shank and rod portions being such as to provide a fluid leak-proof seal between the same and the walls of said valve bore.

The plug 136 as aforementioned, is threadedly disposed in its accommodating bore and consequently upon advancing the same into the latter the nose 143 of the needle valve is brought into selective spaced relations with the communicating inlet port to thereby provide a predetermined size of orifice for the ingress of fuel into the housing chamber connecting with the latter. Spring 136a retains plug 136 in its adjusted position.

The needle valve is likewise disposed in its bore to locate groove 1511 in communication with its associated transfer port 123a, 12411 to thereby enable fuel to ingress to the valve bore and through the aforesaid orifice to the housing chamber.

With the engine in idle, each of the needle valves is rotatably adjusted through its plug 136 to bring the groove into predetermined registry with its associated inlet port 123a, 124a so as to define its idle posit-ion and thus to permit a sufficient quantity of fuel to enter the chambers 22 and 23 which, when mixed with the previously metered fuel and the idle air supply, provides an explosive mixture of the above proportions of said components.

Each of the needle valves is also responsive to the speed of the engine to variably regulate the quantity of 'fuel entering the housing chambers.

For this purpose, each needle valve is provided with a pinion which is adapted to mesh with a rack 162 formed on the underside of the valve rod 102. Look screw 163 carried in the housing 20 is adapted to engage flat 164 provided on the upper surface of rod 102 and prevent its rotation and hence disengagement of the rack and pinion.

With this assembly, as the valve rod 1112 is reoiprocated through the housing bore 91 it will effect the rotation of each of the needle valves 134 so as to bring its valve groove 150 into selective communication with the inlet ports 123a and 1245a and thus vary the quantity of fuel entering into each of the respective housing chambers.

The cam 27 is linkably connected by lever 165 to the throttle linkage 16 in the same manner as cam 47 whereby as the operator actuates the throttle controls to accelerate the vehicle, the rotation of linkage 16 is also effective to slide said cam 97 in a downward direction as viewed in FIG. 2. The valve rod 102 moves to the 'left so as to rotate each of the needle valves 134 in proportion to the acceleration of the vehicle.

The valve groove 150 of each needle valve is thereby Totatably moved progressively out of registry with its associated inlet port 123a, 124a, and when the engine speed is increased to a predetermined value, for example to a speed representing a vehicle velocity of approximately 25 miles per hour, said valve groove is completely out of registry with said inlet port thereby stopping the fuel flow therethrough.

At this accelerated vehicle velocity, the engine is being supplied, as is aforementioned, with a suitable carbureted fuel by the conventional carburetor assembly.

The idle fuel needle valve assembly is also intended to 9 be operable to variably regulate the fuel flow into the housing chambers 22 and 23 during the deceleration cycle of the engine in a manner as will now be described.

As previously mentioned, at the initiation of the deceleration engine cycle, the vacuum in the intake manifold immediately increases from 1649 inches of mercury to approximately 26-28 inches of mercury, and thereafter as said cycle progresses said vacuum likewise decreases proportionately to its lower value. v

This transitional vacuum condition is utilized to provide said variable regulation of the aforesaid fuel needle valve assembly.

As best seen in FIG. 2, a port 175 is formed in the housing 20 and is seen to communicate at its inner end with piston chamber 92 in such manner as to be the left of said piston.

A conduit 1'78 connects at one end to said port and at its opposite end to the engine intake manifold whereby the variable vacuum characteristics of said engine is transmitted to said chamber 92.

As the operator initiates the deceleration of the engine,

the resultant instant increase in vacuum is operable to hold the piston 94 in the accelerated position therefor against the resistance of spring N3 so as to retain the groove 150 of each needle valve 134 out of registry with its respective inlet fuel port 123a, 124a.

Simultaneously, the slug of air enters the housing chambers 22, 23 as aforementioned through the idle air valve assembly, and mixes with the dense fuel in the intake manifold so as to lean said fense fuel and consequently provide a mixture of the desired proportions of fuel and air.

Thereafter, as the deceleration cycle continues, the manifold vacuum also progressively decreases hence decreasing the inlet air in proportion of the consumption of the dense fuel in said manifold.

During this interval, the force of spring 1% overcomes the vacuum condition in chamber 92 and therefore results in reversibly rotating the needle valves 13d toward their idle position.

As said valves approach their idle position and at a predetermined engine speed in the deceleration cycle, the fuel grooves 150 of said needle valves are brought into maximum registry with their respective inlet ports 123a, 124a so as to inject a slug of fuel into the chambers 22 and 23.

This is usually undertaken at the instant the dense fuel has been consumed and the carbureted fuel starts to become overly lean.

It has been determined that this occurs at approximately an engine speed representing a vehicle velocity of 15-25 miles per hour.

As a result the injected fuel slug mixes with the air provided by the idle air valve assembly to provide a fuel mixture of continued optimum proportions.

Thereafter, as the deceleration cycle continues, the decreas in vacuum modulates both the air and fuel valve assemblies so as to continue to provide an optimum fuel mixture, the transitional deceleration cycle ending upon the engine reaching its idle speed and the fuel and air valve assemblies returning to their respective idle positions.

In FIG. 5 is'herein shown a modified piston 185 which may be substituted for the piston 40, the instant construction differing in that it is formed having end bells 186 which are preferably identical in configuration.

The piston 185 is disposed in the housing bore 32, being spring centered by suitable springs 188 and 189 interposed respectively between one end of said piston and the plug 57, and between the opposite end of said piston and the valve rod 44 in an idle position with respect to inlet port 24 and transfer port 35 and thus effective to regulate the flow of air into the housing chambers 22 and 23.

With this assembly, as the engine controls are actuated by the operator to acceledate the engine in the manner previously described, the valve rod 44 is moved to the left effective to move the piston to the left against the resistance of spring 189 to a position wherein the right end bell 1% thereof seals the transfer port 35 from the inlet port 24. to thereby shut oif the idle air flow to the housing chambers 22 and 23.

And, likewise when the engine is decelerated so that it returns to its idle condition, the increase in vacuum in the intake manifold at the begining of said deceleration cycle will literally suck said piston to the left past the inlet port 23 and hence permit a maximum quantity of inlet air to flow to said housing chambers.

And, further as the manifold vacuum progressively decreases during the deceleration of said engine the piston 185 will be returned gradually to its idle position by spring 183 being thus effective as in the previous embodiment to variably regulate the idle air flow to said housing chambers during said deceleration period.

In FIG. 6 another embodiment of carburetor structure is herein shown and differs from the carburetor assembly previously described in that the idle air and fuel valve units are controlled through a lever assembly that is common to both of said valve units.

Specifically, the instant carburetor structure is seen to include a housing Ztll provided with a pair of chambers 2&2 and 203 formed so that upon its attachment to the intake manifold the latter are in substantial longitudinal prolongation to the barrels of the convention carburetor (not shown). A butterfly throttle valve 264 is disposed in each of said chambers and substituted for the butterfly valve in the conventional carburetor barrel, each of said valves being mounted in turn upon a single throttle shaft 2% so as to be rotatable with the same.

One end of said throttle shaft 205 extends outwardly beyond the housing end wall Zilla and carries linkage 2% thereon which is intended to be connectable to the conventional linkage of the carburetor and actuatable thereby to rotate the throttle shaft 205 in the manner as will be hereinafter described.

A pair of valve bores 2&8 and 2b? are formed in the carburetor housing 261 extending therethrough in substantial parallel spaced relation to each other, each of said bores communicating at its inner end with one of the housing chambers 292, 283.

Ports 212 and 213 communicate at one end respectively with valve bores 2G8, 209, the other end of each of said ports communicating in turn with one of a pair of fuel transfer ports formed in the conventional carburetor housing such as the ports 131, 132 of the previous carburetor assembly.

A idle needle valve sleeve 215 is disposed in each of the aforesaid valve bores 288, 2&9, said valve sleeve likewise being provided with a slot 218 formed in the wall thereof so as to be moved into registry with the fuel inlet port 212, 213 associated therewith.

Each of the needle valve sleeves 215 is preferably attached at its remote end to a plug 219 threadedly disposed in the valve bore so as to be rotatable relative thereto, each of said plugs being adjustable to thus 10- cate the slot 218 thereof in preselected registry with its inlet port so as to provide an idle supply of fuel to said connected housing chambers.

An idle air control assembly is also provided in the housing for regulating the idle air inlet to the carburetor.

For this purpose, a bore 256 is formed in the housing 201, being preferably spaced centrally between the aforementioned bores 2%, 209, the inner end of said bore communicating with a pair of transfer passageways 257, 258, the opposite end of the latter connecting respectively with one of the housing chambers 202, 203.

In idler air valve sleeve 260 is disposed in said bore 256, said sleeve having an elongated slot 262 formed therein adjacent its inner end and which is intended to register with an air inlet port 263 provided in the housing 201 and communicating with a suitable source of clean air.

Said valve sleeve 260 is preferably attached at its outer end to an adjusting nut 265 threadedly disposed in said bore 256, said nut being readily adjustable to carry the slot 262 into selective registry with said inlet port and to thereby provide for a predetermined quantity of idle air to the housing chambers.

The idle air and fuel valve control assemblies are also intended to be variably actuated as in the aforementioned carburetor structure to regulate the quantity of air and fuel directed to the housing chambers 202, 203 during the acceleration and deceleration cycles of the engine.

For this purpose, a valve bore 220 is formed in the housing 201, extending longitudinally therethrough adjacent the side wall 201b of the latter, said bore communicating with each of the valve bores 208, 200 and 255.

Rod 221 is disposed in said housing bore 220 and is formed with a rack on its one surface thereof as identified at 223 and which is adapted to mesh with a pinion 225 mounted on each of the idler valve sleeves 215 and 260.

One end of said rod is seen to be integrally formed with a piston 226 the latter being disposed in chamber 227 communicating with the aforesaid bore 220. Plug 228 threadedly disposed in the end of the chamber 227 is thus eifective to seal said end thereof from atmosphere.

Passageway 229 formed in the aforementioned housing 201 communicates at its one end with the chamber 227 and at its other end with a conduit 231 the latter connecting at its opposite end with the intake manifold of the engine.

Spring 232 interposed between the plug 228 and the adjoining surface of the piston 226 is effective to urge the rod 221 to the left as is viewed in FIG. 6 to thus normally locate the idle valve sleeves 215 and 256 in their idle position.

A split ring 234 mounted on the rod 221 is adapted to abut against the shoulder 235 defined at the adjoining ends of the chamber 227 and bore 220 to thus locate the idle position for said rod.

A hollow bushing 238 is disposed in the opposite end of the bore 220 and slidably accommodates the opposite ends of the rod 221.

Coil spring 240 interposed between a ring on the rod 221 and a shoulder surrounding the aforementioned bore 220 is also effective to urge said rod to its idle position.

As is aforementioned, the linkage 206 connected to the throttle shaft 205 is connected by any suitable means to the conventional throttle controls for the vehicle, said linkage in turn, being connectable by rod 245 to one leg of an L-shaped lever 246, the latter being pivotally mounted on the housing 201. The remaining leg of said lever carries an actuating finger 248 which is adapted to be extendible into the bushing 238 to thus engage the rod 221 and slidably actuate the same.

With this assembly, upon the operator actuating the carburetor controls so as to accelerate the vehicle, the linkage 206 and 245 are effective to swing the lever 246 in a counterclockwise direction so as to slide the rod 221 to the right and rotate each of the idle sleeve valves 215 and 256 and thereby carry the fuel and air grooves therein progressively out of registry with their responsive inlet ports 212, 213 associated therewith being thus eifective to variably control the quantity of fuel and air entering into the housing chambers 202, 203.

The air sleeve valve 260 is seen to be approximately three times as large in diameter than the fuel sleeve valves 215, the respective inlet ports 212, 213 and 263 being of similar relationship in their diameters as are the aforesaid slots 218 and 262 of said sleeve valves. In like manner, the pinion 225 on the air sleeve valve is approximately three times the diameter of the pinion on 12 the fuel sleeve valve. In this manner, the air sleeve valve 260 is intended to be capable of regulating the air flow therethrough for approximately three times the arcu ate swing in either direction that the fuel sleeve valves 215 may be similarly rotated from the idle position therefor as shown in FIG. 6.

With this relationship, it will be apparent that as the engine speed is increased the fuel valve sleeves 215 will be rotated to a closed position, after which the air valve sleeve 260 will be rotated to its closed position thus disconnecting the fuel and air supply to said housing chambers.

Thereafter, as this accelerated engine speed is continued, the engine is provided with its required carbureted fuel by the conventional carburetor assembly in the normal manner.

Upon initiating the deceleration of the engine by returning the manual carburetor controls to their idle position, it will be recalled that the vacuum of the intake manifold of the engine increased immediately to a magnitude of approximately 26 to 28 inches of mercury.

As this occurs, said vacuum is directed through passage 229 to the chamber 227 and permits the rod 221 to move slightly to the left under the influence of springs 232 and 239 toward its idle position whereby the air valve 260 is again turned on so as to allow a slug of air to enter into the housing chambers 202, 203.

As a result, this injected air mixes with dense fuel which previously condensed onto the walls of the intake manifold to thus provide an optimum mixture of carbureted fuel for consumption during this initial period.

- As this dense fuel is consumed, the velocity of the engine decreases sufiiciently to permit the springs 232 and 239 to progressively overcome the now decreasing vacuum in chamber 227 and to thereby slidably move the rod 221 gradually to the left to its idle position so as to turn on the fuel sleeve valves and thereby permit a predetermined quantity of fuel to again enter into the housing chambers 202, 203 for carburetion therein with the idle air supply.

In FIGS. 7, 8 and 9, a third embodiment of carburetor structure is herein disclosed and is especially designed for use with an internal combustion engine which utilizes a two-piece carburetor of conventional design, comprising an upper housing and a lower housing, the latter normally mounting the throttle valve therefor.

As seen in FIG. 7, the present embodiment includes a housing 303 which is intended to be substituted into the conventional carburetor assembly for the lower housing being thus sandwiched between the upper housing and the intake manifold leading to the engine.

The housing 303 is provided with a pair of housing chambers 304 and 305 which are intended to be longitudinal extensions of the carburetor barrels of the conventional assembly, it likewise being understood that the number of housing chambers may vary according to the number of barrels in the conventional assembly. A shaft 306 rotatably mounted in said housing extends centrally through said chambers and carries a pair of throttle valves 307, 308 therein, the latter being disposed respectively within chambers 304, 305. Suitable conventional controls 309 carried on one end of the shaft 306 are adapted to be connected to the manual controls at the operators station in the vehicle, being operable to rotate said shaft and throttle valves therein between idle position as shown in FIG. 8 and accelerated or open positions therefor.

The housing 303, as may be best seen in FIG. 8, is provided with a bore 310 which connects at its inner end with each of the housing chambers 304, 305 and at its opposite end through conduit 312 to the air filter unit A located thereabove on the upper housing to thus provide a clean supply of air to said chambers.

Valve bore 311 is likewise formed in said housing, intersecting at its mid-point with the aforementioned air inlet bore 310, said valve bore likewise accommodating an idle valve 313. One end of said valve 313 is preferably of reduced diameter so as to accommodate a torsion spring thereon as identified at 315, said spring being interconnected to said valve and a retaining thimble 317 carried on the housing 303.

The opposite end of the valve 313 mounts a yoke 320 so as to be rotatable with the same, said yoke, in turn, carrying a cam follower arm 320a thereon.

Valve 313 is formed with a narrow rib 325 defining grooves 326 on either side thereof, said rib being formed in the portion of said valve disposed in the intersecting bore 310 being thus effective, as will be hereinafter described, to variably regulate the quantity of air flowing through the latter.

As best seen in FIGS. 8 and 9, the housing 303 is also provided with a pair of valve bores 327 and 328 which extend inwardly from the side Wall 30% thereof on the side opposite the bore 310, each of said valve bores terminating in a port 331, 332 respectively, which as best seen in FIG. 8 communicates with the housing chambers 305, 304.

As best seen in FIG. 9, a secondary fuel transfer passage 338 is formed in the housing preferably directly above each of the valve bores 327, 328, each of said passageways communicating with one of a pair of ports 340 extending upwardly from the bottom face of the housing 303 and communicating with the valve bore closely adjacent its housing port.

Bore 345 formed in said housing so asto extend longitudinally therethrough closely adjacent the housing side wall 30317, is preferably spaced above the transfer passage 338 associated with each of said valve bores 327, 328, said bore 345, in turn, communicating with each of the latter by means of ports 3%.

A primary fuel transfer passage 350 is likewise seen to be formed in the housing extending inwardly from the side wall 30312 thereof directly above each of the secondary transfer passages 338, the outer end of said primary passage being sealed by plug 351. The opposite end of each of said primary transfer passages communicates with one end of one of a pair of grooves 352 which are similar in disposition and function to the grooves 123, 124 in the previous embodiment being thus operable to transfer fuel from the fuel reservoir in the conventional carburetor assembly located thereabove and from the latter to each of the primary passages 350.

An idle fuel needle valve as identified at 361 is threadedly disposed in each of the valve bores 327, 328, and as best seen in FIG. 9 is extendible into the bore 340 and communicating chamber port todefine a predetermined fuel orifice.

To complete the idle fuel valve assembly, a cylindrical valve rod 365 is disposed in the aforementioned bore 345 and is provided with a pair of ports 367 spaced longitudinally therealong, each of which is adapted to communicate through transfer ports 346 formed on either side of said bore 345 to each secondary transfer passage 338.

Torsion spring 370 connectable between said cylindrical rod 365 and the housing 303 through thimble member 372 is operable to urge said rod to its idle position as will be hereinafter more fully described.

With this assembly, fuel may be directed through each of the primary transfer passages 350 and then through the rod ports 367 and communicating transfer ports 346 and secondary transfer passages 338, and hence to bore 340 and communicating ports 331, 332 to each of the housing chambers 304, 305.

The quantity of fuel and air that is permitted to enter into each of the housing chambers is intended to be selectively regulated by means operable to rotate the valve rod 365 and valve 313 in response to actuating the manually operated carburetor controls.

To accomplish this, a yoke member 380, as best seen in FIG. 8, is mounted on the end of the cylindrical rod 365 and is provided with a cam follower arm 380a that is urged by torsion spring 372 into engagement with a cam 390, the actuation of the latter being effective to selectively rotate said cylindrical rod and thus provide the aforementioned regulation of said inlet fuel to the housing chambers.

As best seen in FIGS. 7 and 8, the shaft 306 mounting the aforementioned butterfly or throttle valves extends outwardly from said housing and rigidly mounts a yoke member 385 thereon.

A cam carrier plate 401 is rotatably journaled on said throttle shaft so as to be freely rotatable relative thereto and is provided with a groove of constant radius 403 which is adapted to freely accommodate a finger 404 carried on the aforementioned yoke 385.

The cam carrier plate 401 is seen to adjustably mount the aforementioned cam 390, the latter having a hub portion 330a extendible over the throttle shaft 306 so as to be pivotally adjustable axially of the latter, an adjusting screw 3901: being threadedly carried therein and accommodated in a radial slot 407 formed in the aforesaid cam carrier plate 401.

A second cam as identified at 409 is similarly adjustably mounted on the throttle shaft 306 and cam carrier plate 401 and extending outwardly radially from the latter preferably diametrically opposite the cam 390 and is adapted to be operable with the cam follower 320a for controlling the positioning of the idle air valve assembly for the regulation of idle air to said housing chambers.

As seen in FIG. 7, the idle air and fuel valve assemblies and the actuating cam drive therefor are shown in their respective idle positions.

In this position the cam follower arm 308a is engaging the edge 390a of cam 390 and cam follower arm 320a is in engagement with edge 409a of cam 409.

Upon the operator actuating the throttle controls to accelerate the vehicle, the throttle valve shaft 306 is rotated in a clounterclockwise direction from its idle position as shown in FIG. 7 so as to swing the cam carrier 401 and each cam follower arm 320a and attached yoke 320, 380 in a clockwise direction effective to rotate the idle air valve 313 and idle fuel valve rod 365 and thereby progressively diminish the quantity of air and fuel flowing into the housing chambers 304, 305.

As in the previous embodiment, the air valve 313 and associated porting are of such relative size compared to the rod 365 and ports 367 therein that the air may be regulated through an arcuate swing of valve 313 that is approximately three times as large in either direction from the idle position therefor as compared to the arcuate regulatory swing of fuel rod 365.

At the end of approximately a 20 degree rotation of each cam 390 and 409 which represents approximately a vehicle speed of about 30 to 25 miles per hour, the cam follower on each of said yokes is adapted to slide over and upon peripheral surface 320b, 390b, of their respective cams which surface, as seen in FIG. 7, is at constant radius relative to the center of rotation of the throttle shaft being thus effective to stop any further rotation of said air valve 313 and fuel valve rod 365. At this instant, the air and fuel valve assemblies are moved to their off positions whereafter the vehicle is provided with fuel through the conventional carburetor assembly located thereabove, the throttle valves 307, 308 being in the accelerated open position so as to permit said carbureted fuel to pass freely through the housing chambers 304, 305.

Upon initiating the deceleration of the vehicle the cam carrier is permitted to rotate slightly clockwise from its accelerated position to a dwell position so as to relocate the follower 320a in engagement with edge 409a of cam 409 being thus effective to open said idle air Valve assembly and direct a slug of air into the housing chambers.

For this purpose, a suitable diaphragm motor 425 is municating with the intake manifold of the engine to thus direct the vacuum condition of the latter to said motor inlet.

During the acceleration cycle, the vacuum of the intake manifold is approximately at 16 inches of mercury, and the vacuum motor is in its rest position. During this interval, the end of connector rod 428 slides freely through the slot 430 to thus permit said carrier plate to move to its accelerated position.

Thereafter, when the deceleration of the vehicle is initiated and the vacuum of the intake manifold immediately increases to approximately 28 inches of mercury, the diaphragm motor is actuated to pull its piston rod 426 to the right as viewed in FIG. 7 which is eifective to catch the carrier plate 401 as it is rotating toward its idle position and is effective to hold said plate in a partially actuated or dwell position.

At this dwell position the air valve assembly is turned on to permit a slug or air to enter the housing chambers 304, 305 and mix with the dense fuel to provide an optimum carbureted mixture to the engine intake manifold.

And, as this dense fuel is consumed, the intake manifold vacuum progressively decreases so as to enable the piston rod 426 to gradually move toward its idle position thus permittingthe cam carrier plate 401 to return to its idle position during which time the idle fuel valve assembly is again turned on to thereby continue to provide a proper carbureted fuel mixture to the engine intake.

Having described the carburetor structure of the present invention in several of its preferred embodiments it will be realized that it is susceptible to various modifications, arrangements and combinations without departing from the inventive concepts as are defined in the appended claims.

What is claimed is:

1. In a carburetor assembly having a body provided with a carbureting barrel for connection to the intake of an internal combustion engine and to which are directed primary sources of fuel and air for carburetion and throttle controlling primary valve means in said barrel actuatable between idle and accelerating positions for l6 s regulating the flow of carbureted fuel to said engine intake, a housing disposed between said carburetor body and engine intake, means in said housing defining a carbureting chamber in communication with said barrel, means for supplying secondary sources of fuel and air to said chamber, secondary valve means movably disposed in said housing between said secondary sources of fuel and air and said chamber, means connecting said secondary valve means to said primary valve means including link means connected to said primary valve means, rack means slidably supported in said housing, pinion means on said secondary valve means in meshing engagement With said rack means, cam means connected to said link means and in engagement with said rack means and responsive to the movement of said primary valve means to its idle position to actuate said secondary valve means and direct a predetermined additional quantity of fuel and air into said chamber, cylinder means in said housing, piston means disposed in said cylinder means and in engagement with said rack means, and conduit means conmeeting with said cylinder means and the intake of said engine, said piston means being responsive to a change in the vacuum conditions in said engine intake as the engine is decelerating toward its idle speed to actuate said secondary valve means and variably regulate the quantity of fuel and air directed to said chamber.

2. In a carburetor assembly as is defined in claim 1 and wherein the cam means are adjustable on said housing to provide a predetermined idle position for the secondary valve means.

3. In a carburetor assembly as is defined inclaim 1 and wherein the sources of secondary fuel and air are separately applied to said housing.

References Cited by the Examiner UNITED STATES PATENTS 2,040,020 5/36 Parker 261-41 X 2,071,717 2/37 Winkle 26l51 2,162,056 6/39 Bracke 26141 X 2,261,794 11/41 Carlson et al. 261-41 2,261,992 11/41 Goldi 12397 2,279,626 4/42 Lehew 26141 2,327,592 8/43 Chisholm 26141 X 2,353,524 7/44 Stone 26l4l X 2,652,237 9/53 Boller 26l-41 X 2,853,064 9/58 Karrasch 12397 3,076,639 2/63 Szwargulski et a1. 261--34 HARY B. THORNTON, Primary Examiner.

HERBERT L. MARTIN, Examiner. 

1. IN A CARBURETOR ASSEMBLY HAVING A BODY PROVIDED WITH A CARBURETING BARREL FOR CONNECTION TO THE INTAKE OF AN INTERNAL COMBUSTION ENGINE AND TO WHICH ARE DIRECTED PRIMARY SOURCES OF FUEL AND AIR FORCARBURETION AND THROTTLE CONTROLLING PRIMARY VALVE MEANS IN SAID BARREL ACTUATABLE BETWEEN IDLE AND ACCELERATING POSITIONS FOR REGULATING THE FLOW OF CARBURETED FUEL TO SAID ENGINE INTAKE, A HOUSING DISPOSED BETWEEN SAID CARBURETOR BODY AND ENGINE INTAKE, MEANS IN SAID HOUSING DEFINING A CARBURETING CHAMBER IN COMMUNICATION IWTH SAID BARREL, MEANS FOR SUPPLYING SECONDARY SOURCES OF FUEL AND AIR TO SAID CHAMBER, SECONDARY VALVE MEANS MOVABLY DISPOSED IN SAID HOUSING BETWEEN SAID SECONDARY SOURCES OF FUEL AND AIR AND SAID CHAMBER, MEANS CONNECTING SAID SECONDARY VALVE MEANS TO SAID PRIMARY VALVE MEANS INCLUDING LINK MEANS CONNECTED TO SAID PRIMARY VALVE MEANS, RACK MEANS SLIDABLY SUPPORTED IN SAID HOUSING, PINION MEANS ON SAID SECONDARY VALVE MEANS IN MECHING ENGAGEMENT 